Find the 50th term of the following series: 1 + 3 + 7 + 13 + 21 + ............ Answer: 2451 Explanation t2 – t1= 2 (2*1) t3 – t2= 4 (2*2) t4 – t3 = 6 (2*3) ……………………….. ………………………… ……………………….. t50 – t49= 98 (2*49) Adding all the equations, we get t50 – t1= 2 + 4 + 6 + ………. + 98 t50 – t1= 2450 t50 – 1 = 2450 Therefore, t50 = 2451 … [Read more...] about Sequences Series – nth term
GRE Arithmetic Theory & Practice Questions
More than one answer – Number Properties
Let S be the set of all positive integers n such that n^2 is a multiple of both 24 and 108. Which of the following integers are divisors of every integer n in S? Indicate ALL such integers. a) 12 b) 24 c) 36 d) 72 Solution: A, C Explanation It is given that n2 is a multiple of both 24 and 108. So the least such n2 will be nothing but the LCM of 24 and … [Read more...] about More than one answer – Number Properties
Numerical Entry – Permutations and Combinations
A manager is forming a 6-person team to work on a certain project. From the 11 candidates available for the team, the manager has already chosen 3 to be on the team. In selecting the other 3 team members, how many different combinations of 3 of the remaining candidates does the manager have to choose from? Answer: 56 Explanation The manager has to form a 6-person … [Read more...] about Numerical Entry – Permutations and Combinations
Quantitative Comparison – Number Properties & Theory
Compare Quantity A and Quantity B, using additional information centered above the two quantities if such information is given, and select one of the following four answer choices: (A) Quantity A is greater. (B) Quantity B is greater. (C) The two quantities are equal. (D) The relationship cannot be determined from the information given. N = … [Read more...] about Quantitative Comparison – Number Properties & Theory